Michael Stewart, 60, on Sunday penned a record 500th marathon - an incredible accomplishment that gains him a southern hemisphere record.

And he has no intention of stopping there.

"I want to do one at 100 clicks," he says.

"But that's still 40 years away."

Stewart's first marathon was in 1970, the Wellington Olympic Harrier, and he has never looked back since.

Competing in 499 marathons in 42 years around the country, he ran his 500th from Pinehaven and back supported by the growing "100 Club" made up of people who have completed 100 marathons or more.

Stewart says he is known as the "Rainbow Man" because of his outrageously colourful running gear.

On Sunday, he ran the length sporting a pink outfit, a choice made because "pink is the colour of love".

The goal of competing was to finish.

He enjoys the buzz and the sense of achievement crossing the finish line.

"I did it in just over five hours."

"But all that matters is crossing the line."

He says if he had done what a lot of people do and gone hard for fast times he didn't know how long his body would hold together.

"Some people used to say to me, 'what are you doing all these marathons for? Train hard and do a good one!'.

"All the ones who said they were busting their guts to do good times . . . and they ain't around now." A mix of running and cross training has kept him fit; using a mini tramp, an ab- machine, and doing yoga are all part of the mix.

"And I go dancing." Stewart credits his vegan diet and his beliefs in the harmony of the yin and yang.

Stewart's family, mayor Wayne Guppy, and other competitors recognised the milestone on Sunday before heading to the Petone Working Men's Club for celebrations.